WSVA7-0393
DSAVA: HEALTHY BREEDING
HOW DO INHERITED DISEASES AFFECT OUR PRACTICE?
B. Bonnett1
1International Partnership for Dogs, IPFD, Georgian Bluffs, Canada
HOW DO INHERITED DISEASES AFFECT OUR PRACTICE?
Brenda N. Bonnett, DVM, PhD
CEO International Partnership for Dogs and B Bonnett Consulting, Canada
brenda.bonnett@ipfdogs.com
This paper is the first in a series on Health Breeding, including the veterinarian’s role. Here we look at what is included under the heading of ‘inherited disease’ and identify opportunities and challenges as veterinarians address these issues.
What disorders do veterinarians see in practice?
From the UK, VetCompass data say ears, teeth, anal sacs, nails, arthritis, diarrhea, obesity and injuries top the list (1). These include the most common and routine conditions that may affect any dog. From Swedish insurance data (2006-2013) (Personal communication, Bonnett, BN), where routine procedures like nail trims and teeth cleaning are not covered, the most common conditions were: vomiting/diarrhea/gastroenteritis; skin tumours; skin trauma; otitis; pain/locomotor problems; inflammatory skin problems; pyometra; mammary tumours; anal/perianal problems; nail trauma; and itching. Which of these conditions might be considered inherited? Well, there may be a genetic predisposition for ‘everything’. Are Jack Russells predisposed to
have vehicular accidents because of their inherent temperament? Perhaps, but for the sake of discussion, let’s address this in terms of how inherited disease might present to a veterinarian with reference to testing.
Who comes to veterinarians asking for or needing ‘DNA tests’?
1. Individual owners with a pet dog. What does inherited disease mean to them?
a. Symptomatic dog: diagnosis and prognosis; e.g.:
I. Potential response to treatment (e.g. genomics to optimize cancer chemotherapy) (2)
II. Genetic typing on tissues (e.g. tumours)
III. Why did this happen/ what or who is to blame?
b. Asymptomatic dogs: identifying increased risk; early detection (e.g. bladder cancer; however, this needs to be accompanied by an effective intervention)
c. Interpreting the results of ancestry tests submitted by the owner. Just for fun? Or can these be used to inform care?
d. Identification and parentage testing for forensic, or legal reasons.
2. Breeders – a casual breeder vs. a registered breeder vs. commercial breeders.
a. Decisions about the individual dog, mate selection, etc.
bComplying with regulations/recommendationsi.Impact on the breed / population; concerns about genetic diversity (3)
So, there is a wide range of interactions in practice
that might involve inheritance and genetic testing. One hears a lot in the media about inherited disease in pets, especially dogs. However, decision-making based on the media or discussions on Facebook is not necessarily the best for health and welfare of dogs. A television documentary, Pedigree Dogs Exposed, for example, highlighted syringomyelia in Cavalier King Charles Spaniels as a terrible disease affecting young dogs.
The reaction led to worldwide calls for health programs for this disease. Notwithstanding the importance of
this disease, it is not the most common nor highest
risk cause of death in this breed (Figure 1); we should promote a balanced approach to breed-specific health issues that considers all health problems in a breed.
Figure 1: Most common causes of mortality: Rates from Swedish insurance data 2006-2011
The prevalence of inherited disease in dogs: Information and misinformation.
We know that veterinarians and clients have access
to massive amounts of ‘information’ on the internet. There is an abundance of sophisticated marketing; exaggerations and inaccuracies lurk amid useful information; differentiation may be challenging. However, defining the most important health issues requires that we understand both prevalence and risk of various conditions.
An Urban Experience
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